Rear Axle Build: Advise Needed

[aaronu]

im new to the site, so please, bear with...

2000 Chevy K2500 factory ride height (OBS) CCSB, Factory Spec 5.7, 3.73 8 Lug. 265/75/16 BF Goodrich A/T's (everything is stock as of now. no mods)

that's what she's got. she's not quite my truck of choice, but she gets the job done. so far...

now, iv got rear drums, and a half float axle. I do a lot of towing, and the more I tow, the heavier the loads get. I cross the country at least 3-4 times a year. this is the advise iv been given by ppl i know...

1) go to a full floating axle
Q) can I find a full float with a 3.73? its gotta be the same as the front diff...

2) factory rear discs from NBS or NNBS
Q) aside from a proportioning valve, (I think that's what it's called) will I have any other things to worry about? prob wheel diameter... (16' OE steel rims)


3) will the yoke for the u-joints be the same size? if not can I change that out, or do I have to chase that all the way down my drive line?

4) i want a limited slip back there. im already assuming i'll have to rebuild the whole thing, bearings, seals and the like, so, when I open it up, how will I know if I need to replace the diff? do limited slip's wear out?
last set of thoughts...

is this all justa pipe dream? bottom line: im looking for a 8 lug HD 3.73 full float with a limited slip diff and factory disc brakes... am I looking for a unicorn? do they actually exist? or am I on the wrong path all together? is there a better choice that I don't know about? (ppl tell me to get a new truck. long story, I cant. I make do with what iv got) even if I put $1500 into a rear axle, it'd be bullet proof.

thanks in advance for the thoughts.

 

[sewlow]

From my experience. Other's here are more knowledgeable, but this may get you going in the right direction.

1. Yes!
https://www.ringpinion.com/Content/Book/Semi-Float-vs-Full-Float.pdf

FF's in a GM are usually what's commonly referred as a 'Corporate' diff. & are the same from about the '70's on. When I was looking for one, I came upon more with 4.11's than 3.73's, but they're out there. Mind you, I wasn't looking for the disc option. I was keeping to the drum versions.

Know how to figure the ratio without removing the cover? Mark the axle hub to the housing. Same for the pinion. Turn the axle 10X. Count how many times the pinion rotates. Move the decimal point over on the final answer. 10x = more accurate.

2. Sure. Ether/or. Use the GMT800 master. Bolts in. There's a thread here on how-to.
16" wheels should be no prob.

3. Mine bolted in. But I'd check that. There are conversion U-joints available for stuff like that.

4. LSD's do wear out, but they are completely rebuildable. Comes in a kit for specific apps. Easy process! Check with Co.'s such as 'Randy's Ring & Pinion'. There's others.
A bearing rebuild kit is common too.

https://www.ringpinion.com/

http://www.drivetrainamerica.com/19689-010-eaton-posi-gm-chevy-10-5-14-bolt-limited-slip-4-10-down/

8 lug HD 3.73 full float with a limited slip diff and factory disc brakes are out there. No unicorn!

Anyone with more experience can jump in here now & add-to or correct any mistakes I've made! Lol! But like I said, this is just from my experience.

 

[heavyjunk]

I've swapped many a full float 14 bolt in place of 12 (and even 10)bolt rear ends. You'll want to get it from '88 or newer, as pre "88 had a narrower frame. Not sure about NBS frame width though, so make sure you measure your spring perches.

Why do you want disc? If your trailer has adequate brakes I would say working, adjusted drum brakes would be just fine for towing, and would be cheaper and easier to swap in. Just my opiniion though.........

This is also a good time to add extra leafs